A sustainable way of increasing productivity of coconut cultivation using cover crops: A review

Abstract

Coconut, as one of the main components of the daily Sri Lankan diet and one of the predominant crops grown in different agroecological zones except in higher elevations, has become a major export-earning crop at present. Its productivity is limited by adverse climatic changes in coconut growing areas, biotic and abiotic stresses, and poor agronomic practices. Cover cropping has been identified as a rewarding and time-tested farming solution that increases the productivity of most coconut lands while addressing the above issues. It is the practice of growing plants for modifying soil properties, controlling pests and diseases, facilitating crop growth and yield, reducing chemical dependency, enabling the coconut-animal farming system, and generating extra profit. Legumes, fodder and pasture grasses have been identified as the common and trending cover crops for Sri Lanka. Comprehensive knowledge of selecting suitable cover crops, planting materials and proper agronomic practices are important for a successful cover cropping system under coconut. Farmers avoid this practice due to their ignorance on cover cropping, and its benefits, and due to the aggressive characteristics of cover crops such as reappearing behaviour, being an alternative host for pathogens, and competitiveness for natural resources. In this review, the unique attributes of common cover crop species were explained. Furthermore, the variety of on-farm benefits and ecosystem services of cover cropping and some important agronomic considerations were reviewed. Finally, future research potential for recommending new species and their adaptability to a wide range of ecological and ecosystem circumstances under coconut cultivation were investigated.